Dain

Dain is a purple haired boy from Lief's and Jasmine's age, he is calm and quiet and wouldn't seem to harm anyone unnecessarily. His parents were killed when he was young but Doom found him and let him join the resistance against the shadow lord. He is very knowledgeable about the Shadowlord's Ols, monsters which can take on any form, he also knows royal archery.
At the end of the series he is revealed to be a third rank ol, taking on the form of his own dagger to know where and when Lief and his squad will make their move. Joker, of course, didn't know about this.